New Zealand Daylight Saving period extended

A DESCRIPTION OF THE PROBLEM :
New Zealand government has announced an extension to the daylight saving period.

See offical announcement http://www.dia.govt.nz/diawebsite.nsf/wpg_URL/Services-Daylight-Saving-Daylight-saving-to-be-extended?OpenDocument

Does this require a change to timezone data? The lead time (change effective in September this year) seems quite short.

REPRODUCIBILITY :
This bug can be reproduced always.